Archaeologists have unearthed 57 ancient Egyptian tombs, most of which hold an ornately painted wooden sarcophagus with a mummy inside, it was announced today.

The oldest tombs date back to around 2750BC during the period of Egypt's first and second dynasties. Twelve belong to the 18th dynasty which ruled Egypt during the second millennium BC.

The discovery throws new light on Egypt's ancient religions, the country's Supreme Council of Antiquities said.

Egypt's archaeology chief, Zahi Hawass, said the mummies dating back to the 18th dynasty are covered in linen decorated with religious texts from the Book of the Dead and scenes featuring ancient Egyptian deities.

Abdel Rahman el-Aydi, head of the archaeological mission that made the discovery, said some of the tombs are decorated with religious texts that ancient Egyptians believed would help the deceased to cross through the underworld.

Aydi said one of the oldest tombs is almost intact, with all of its funerary equipment and a wooden sarcophagus containing a mummy wrapped in linen.

In 31 tombs dating to around 2030-1840BC, archaeologists discovered scenes of different ancient Egyptian deities, such as the falcon-headed Horus, Hathor, Khnum and Amun, decorating some of the tombs.

The findings were unearthed at Lahoun, in Fayoum, 70 miles south of Cairo.